Microsoft believes you own emails stored in the cloud, and that they have the same privacy protection as paper letters sent by mail...
The U.S. government can obtain emails only subject to the full legal protections of the Constitution's Fourth Amendment...
A search warrant cannot reach beyond U.S. shores...
[The US government] argues that your emails become the business records of a cloud provider. Because business records have a lower level of legal protection, the government claims that it can use its broader authority to reach emails stored anywhere in the world.